Automatic plants for industrial washing can be of various types, both as concerns the kind of treatment (immersion, spray washing, use of water-based detergents, or of trichloroethylene type solvents), and as concerns the automatic handling of the mechanical pieces being treated (screw or carousel conveyors, parallel vertical chain or horizontal chain conveyors, and the like).
The present invention concerns the most diffused type of automatic plant--as that described in DE-A-2047537 --comprising one or more washing tanks and loading and unloading stations, positioned on a line, as well as an automatic conveyor which collects the pieces from the loading station, moves them from one tank to the next, and discharges them in the unloading station.
The pieces are usually arranged into baskets of suitable shape. Hooking and release of the baskets are obtained, according to known technique, by providing said baskets with specially shaped handles with which snaps into engagement a hook fixed to the arm of an automatic conveyor.
Further according to known technique, to complete the automatic handling system of the pieces and to reduce the dwell time in the loading and unloading stations, for positioning and picking up the baskets, provision is made of two motored belt or roller conveyors, acting as provisional storage units and allowing the plant to have sufficient autonomy to require no intervention by the operator.
The drawbacks of such known plants can be summed up as follows:
use has to be made of special baskets, wherein the cited shape of the respective handles limits the accessibility when filling and emptying the baskets; these baskets are moreover quite bulky and difficult to stack into piles; they finally involve considerable costs; PA1 the belt or roller conveyors involve considerable costs--also due to the presence of the necessary motion control devices--which heavily weigh on the general cost of the plant; they involve additional costs also from the maintenance point of view; finally, they take up a lot of space on the ground, which increases the more the autonomy required from the plant.